Power efficiency is important for operators of single computing nodes (e.g., cell phones, Smartphones, tablets, Ultrabooks®, notebooks, laptops, desktops, servers) as well as operators of computing node groups (e.g., datacenters, cloud computing operations, and/or computing cluster operations comprising large numbers of computing nodes such as servers). Conventional power efficiency monitoring systems focus at a “low level”, such as the computing load experienced by individual cores of a single processor included in a server.